The invention relates to a method for operating an electrical distribution system which has a first energy store and a second energy store.
Electrical distribution systems for vehicles usually have an energy store in the form of a lead-acid rechargeable battery. The lead-acid rechargeable battery often requires regeneration, however. This regeneration can last up to 24 hours. Since a normal running operation of a vehicle does not last so long, the regeneration is usually distributed over several running cycles.
The object on which the invention is based consists in providing a method and an apparatus which contribute to an energy store of an electrical distribution system being regenerated.
The object is achieved by the features of the independent patent claims. Advantageous configurations are characterized in the dependent claims.
The invention is characterized by a method or an apparatus for operating an electrical distribution system. The electrical distribution system has a first energy store and a second energy store. The two energy stores are connected in parallel. Characteristic values of the first and/or the second energy store are detected. A regeneration phase of the first energy store is implemented depending on the detected characteristic values. In the regeneration phase, a first operating voltage is preset and provided by means of a generator in such a way that said first operating voltage contributes to the second energy store having, after a preset time span, a higher open-circuit voltage than the first energy store.
Owing to the fact that the two energy stores are connected in parallel, it is possible for the first energy store to be recharged as soon as the second energy store has a higher open-circuit voltage, even if the generator is no longer in operation. It is therefore possible for the first energy store to be further regenerated although a running cycle of the vehicle is completed. By virtue of the regeneration phase being implemented depending on the characteristic values, it is also possible for the regeneration to only be implemented when it is expedient, for example in the case of a specific preset battery temperature of the first energy store.
In accordance with an advantageous configuration, once a preset state of charge of the second energy store has been reached, a second preset operating voltage is provided by means of the generator, which second preset operating voltage contributes to the first energy store being charged and the second energy store approximately maintaining its state of charge. As a result, for example, the second energy store can be charged more quickly using a higher first preset operating voltage and, for example, in the case of a state of charge of 90% capacity, with setting of the second preset operating voltage, can contribute to the first energy store being charged further.
In accordance with a further advantageous configuration, during the regeneration phase, characteristic values of the first energy store are monitored. Thus, the regeneration can be checked and possibly ended, for example, if characteristic values fall below or exceed preset threshold values.
In accordance with a further advantageous configuration, the electrical distribution system has a switch, by means of which the first energy store can be galvanically isolated from the second energy store. As a result, the safety of the electrical distribution system can be increased since it is possible to galvanically isolate the two energy stores from one another, for example if one of the two energy stores is defective.
In accordance with a further advantageous configuration, the first energy store has a lead-acid rechargeable battery. Precisely in vehicle electrical distribution systems, this is a robust and inexpensive energy store.
In accordance with a further advantageous configuration, the second energy store has a lithium-ion rechargeable battery. This is characterized by the fact that it can be charged quickly and has a higher open-circuit voltage than a lead-acid rechargeable battery in the case of a suitable composition.
In accordance with a further advantageous configuration, if there is no or still only a preset low charge flow between the first energy store and the second energy store, a check is performed, depending on the detected characteristic values, to ascertain whether the regeneration phase was successful. As a result, for example, if the regeneration phase has not yet been successful, it is possible to store the fact that a further regeneration phase is required, for example in the next running operation. As an alternative or in addition, if the regeneration phase was successful, it is possible to store that the regeneration has been implemented successfully.
Exemplary embodiments of the invention are explained in more detail below with reference to schematic drawings, in which:
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.
Elements with the same design and function are identified by the same reference symbols throughout the figures.